ここから英文です。 These discrete units of sounds are not arbitrarily combined; the sequence of such units is under certain restrictions. For example, there is no English word which begins with ten consonants. Furthermore, the consonants which can appear in the iinitial clusters of English are restricted. Thus for a three-consonant cluster beginning with /s/, the second consonant can only be one of /p,t,k/. Such restrictions are found in many languages, and one of the purposes of the study of speech sounds is to examine the kind of restrictions peculiar to an individual language.
Therefore, there are several levels in the study of speech sounds: on the one concrete level we try to describe what speech sounds exist, and on the other abstract level we try to examine what regularities govern the realizations of sounds in a langiage.
